The invention relates to a digital-to-analog converter comprising a converting circuit in which a digital signal is converted into a periodical pulse signal from which a direct current signal is obtained by means of a filter circuit which filter circuit has an input circuit which has for the pulse signal a charge time constant which differs from the discharge time constant so that a non-linear relation is obtained between the value of the input signal and the amplitude of the output signal of the filter circuit.
The Dutch Patent Application No. 7 401 003 discloses a converting circuit of the above-mentioned type which is part of an analog-to-digital converter. Therein the input circuit of the filter circuit is constituted by a balanced amplifier having a series circuit of two transistors which are driven by two complementary transistors the collector circuits of which drive the smoothing filter, a series resistor being included in one of those collector circuits.
It is an object of the invention to provide a simpler and cheaper circuit.